Binder for solid electrolyte film formation

Abstract

Disclosed are a binder for forming a solid electrolyte film, which includes a copolymer including structural units derived from a non-polar aromatic vinyl-based first monomer, an aliphatic conjugated diene-based second monomer, and a conjugated polyene-based third monomer, a film-type structure for a secondary battery including the same, and a secondary battery including the film-type structure.

What is claimed is: 
     
         1 . A copolymer binder comprising a copolymer including structural units derived from a non-polar aromatic vinyl-based first monomer, an aliphatic conjugated diene-based second monomer, and a conjugated polyene-based third monomer. 
     
     
         2 . The copolymer binder of  claim 1 , wherein the structural unit derived from the first monomer is included in an amount of 15 to 45 parts by weight based on 100 parts by weight of the copolymer. 
     
     
         3 . The copolymer binder of  claim 1 , wherein the structural unit derived from the third monomer has at least one double bond. 
     
     
         4 . The copolymer binder of  claim 1 , wherein the third monomer has 10 or more carbon atoms. 
     
     
         5 . The copolymer binder of  claim 1 , wherein the copolymer has a block structure including the structural unit derived from the second monomer or the third monomer at at least one end thereof. 
     
     
         6 . The copolymer binder of  claim 5 , wherein in the copolymer, a block structure including the structural unit derived from the third monomer is bonded to at least one end of a random structure including the structural units derived from the first monomer and the second monomer. 
     
     
         7 . The copolymer binder of  claim 5 , wherein in the copolymer, a block structure including the structural unit derived from the second monomer is bonded to at least one end of a random structure including the structural units derived from the first monomer and the third monomer. 
     
     
         8 . The copolymer binder of  claim 5 , wherein the copolymer includes a first block including the structural unit derived from the first monomer, a second block including the structural unit derived from the second monomer, and a third block including the structural unit derived from the third monomer. 
     
     
         9 . The copolymer binder of  claim 8 , wherein in the copolymer, the first block is bonded to one end of the second block and the third block is bonded to the other end of the second block. 
     
     
         10 . The copolymer binder of  claim 1 , wherein in the copolymer, the structural units derived from the first monomer, the second monomer, and the third monomer form a random structure. 
     
     
         11 . The copolymer binder of  claim 1 , wherein the copolymer includes a branched copolymer in an amount of 5 to 75 wt % based on 100 wt % of the copolymer. 
     
     
         12 . The copolymer binder of  claim 1 , wherein the total content of the structural units derived from the second monomer and the third monomer is 60 wt % or more based on 100 wt % of the structural units of the copolymer. 
     
     
         13 . The copolymer binder of  claim 1 , wherein the copolymer has a weight average molecular weight of 100,000 to 1,000,000 g/mol. 
     
     
         14 . A film-type structure for a secondary battery, comprising:
 the copolymer binder according to  claim 1 ; and   at least one selected from the group consisting of a solid electrolyte, a positive electrode active material, and a negative electrode active material.   
     
     
         15 . A secondary battery comprising the film-type structure according to  claim 14 .